Modular low stress package technology

ABSTRACT

A protective modular package assembly with one or more subassemblies, each having a base element, a sidewall element coupled to the base element, and a semiconductor device disposed within and coupled to the sidewall element and the base element; a protective modular package cover having fastening sections located at opposing ends of the cover, torque elements disposed on the opposing ends and configured to fasten the cover to a core, and subassembly receiving sections disposed between the fastening sections with each subassembly receiving section operable to receive a subassembly and having a cross member along the underside of the cover; and an adhesive layer configured to affix subassemblies to respective subassembly receiving sections. The torque elements are configured to transfer a downward clamping force generated at the fastening elements to a top surface of the subassemblies via the cross member of each of the one or more subassembly receiving sections.

PRIORITY CLAIM

This patent application claims priority to U.S. Provisional ApplicationNo. 61/251,460 filed Oct. 14, 2009, which is hereby incorporated byreference.

RELATED APPLICATIONS

This application is related to co-pending U.S. patent applications:application Ser. No. ______, Attorney Docket Number 09-QKT-158;application Ser. No. ______, Attorney Docket Number 10-QKT-128;application Ser. No. ______, Attorney Docket Number 10-QKT-129;application Ser. No. ______, Attorney Docket Number 10-QKT-130, eachfiled on even date herewith, which are incorporated herein in theirentireties.

BACKGROUND

Package designers for power semiconductor devices are faced withnumerous mutually-exclusive goals, necessitating a balance betweenperformance, flexibility, manufacturability, reliability and cost of thefinal product. One elusive parameter to quantify for a new packagedevelopment is the total project cost incurred for engineering andtransferring a robust, high yielding design to a volume manufacturingenvironment. A true total cost calculation is further complicated whenmaterials, process development and assembly equipment aspects arefactored into the equation. A thorough performance assessment andreliability appraisal are also documented to establish that all designgoals have been achieved.

The aforementioned considerations become increasingly difficult tomanage in radio frequency, microwave, and optical applications in whichhigh power levels and harsh environments make it difficult to devise aconsistent methodology with which to characterize all electrical,mechanical and thermal attributes of package integrity. In suchapplications, there is a need to maximize design re-use of processes andmaterials which have previously been qualified for functionality andpurpose.

The designer of semiconductor packaging has available a wide array ofpreviously established materials and principles upon which to build.Applications are generally narrow enough in scope that designers areafforded flexibility to mitigate performance, cost and reliabilityconcerns. However, as the product of operating power and operatingfrequency becomes increasingly large, the options available to thepackage designer diminish greatly, and as a consequence the number ofdifferent packages or packaging technologies required for suchapplications tends to specialize and proliferate, with a resulting drainon resources and escalating costs.

BRIEF DESCRIPTION OF THE DRAWINGS

The accompanying drawings provide visual representations which will beused to more fully describe various representative embodiments and canbe used by those skilled in the art to better understand therepresentative embodiments disclosed and their inherent advantages. Inthese drawings, like reference numerals identify corresponding elements.

FIG. 1 is an isometric view of the underside of a modular protectivepackage cover, in accordance with various representative embodiments.

FIG. 2 is another isometric view of the underside of a modularprotective package cover, in accordance with various representativeembodiments.

FIG. 3 is a cross sectional view of a protective modular packageassembly, in accordance with various representative embodiments.

FIG. 4 is a cross sectional view of a protective modular packageassembly, in accordance with various representative embodiments.

FIGS. 5A-5F illustrate a plate set design in which a protective modularpackage assembly, in accordance with various representative embodiments.

FIGS. 6A-6G illustrate a protective modular package assembly having onesubassembly, in accordance with various representative embodiments.

FIGS. 7A-6F illustrate a protective modular package assembly having twosubassemblies, in accordance with various representative embodiments.

FIGS. 8A-8G illustrate a protective modular package assembly havingthree subassemblies, in accordance with various representativeembodiments.

FIG. 9 shows a top view of a modular package assembly having threesubassemblies, in accordance with various representative embodiments.

FIG. 10 illustrates an exemplary RF straight lead subassembly, inaccordance with various representative embodiments.

FIG. 11 illustrates a prior art assembly having one 4-leaded ceramicleadframe inextricably affixed to a dedicated flange, to form achip-and-wire subassembly.

FIGS. 12A-12B illustrate a modular package assembly in which achip-and-wire subassembly consisting of a ringframe adhesively joined tobase material, itself supporting one or more semiconductor devices, tobe encapsulated in an air-cavity, in accordance with various embodimentsdescribed herein.

FIG. 13 illustrates a prior art assembly having one 2-leaded,chip-and-wire leaded subassembly.

FIGS. 14 illustrates a modular package assembly in which one subassemblysemiconductor devices is encapsulated in an air cavity, in accordancewith various representative embodiments described herein.

FIG. 15 illustrates a prior art circular assembly.

FIG. 16 illustrates a circular modular package assembly, in accordancewith various representative embodiments described herein.

FIGS. 17 and 18 illustrate that bases and sidewalls of the protectivemodular package assembly are interchangeable, in accordance with variousrepresentative embodiments.

FIG. 19 is a flowchart that illustrates a method of manufacturing aprotected package assembly in accordance with various representativeembodiments.

FIG. 20 is a flowchart that illustrates a method of modular packageassembly design, in accordance with various representative embodiments.

FIG. 21 is a flowchart that illustrates use of user input design data todefine configuration and dimension of a modular package assembly design,in accordance with various representative embodiments.

FIG. 22 is a flowchart that illustrates the design and manufacture of adesired modular assembly, in accordance with various representativeembodiments.

FIG. 23 is a flowchart that provides for the modification of the designof a modular assembly, in accordance with various representativeembodiments.

FIG. 24 is a flowchart that provides for the modification of the designand manufacture of a modular assembly, in accordance with variousrepresentative embodiments.

FIG. 25 is a block diagram of a computer system suitable for use inrealizing certain blocks of FIGS. 19-24 in a manner consistent withcertain representative embodiments.

DETAILED DESCRIPTION

Using the drawings, the various embodiments of the present invention,including preferred embodiment(s) will now be explained. In thefollowing detailed description and in the several figures of thedrawings, like elements are identified with like reference numerals.

In accordance with various embodiments disclosed herein, variousstructures, assemblies, and methodologies are disclosed that minimizethe cost and time cost and time obstacles of existing packagingstrategies, without affecting performance and reliability. A modulardesign approach capitalizes on the reuse of proven processes andmaterials. This modular approach comprises a versatile range ofpre-qualified functional blocks or modules arranged to minimizemechanical stress, such that reasonably high reliability can be insuredwith a minimum cost and time-to-market. The disclosed approaches areparticularly well-suited to semiconductor packages for high power radiofrequency, microwave, and optical devices, which are used inapplications with severe operating environments for which low mechanicalstress is a desirable property. With a modular approach to the packagesystem, a new level of flexibility is offered to package designerssince, by combining proven materials with accepted design principles andassembly methodologies, cost-effective semiconductor package innovationscan be released with shortened design and qualification cycles,minimized material inventories, and minimized equipment investment. Atthe same time, designs with this approach may be open-ended, whichallows generational improvements to be implemented as new materials arequalified and released. In contrast, existing package solutions aregenerally frozen upon completion, allowing little margin for continuousimprovements, due to cost prohibitive re-qualification efforts.

Furthermore, by the continued re-use of qualified engineering materialswithin the modular system, package designers can incrementally improveupon existing semiconductor package outlines such that applicationspecialization can accomplished at a drastically reduced cost. Finally,the same concept allows for usage of a wide range of materials,including those engineered with novel thermal and electrical properties,without the requisite impact of a full re-development effort each time anew package is required.

In accordance with certain embodiments a protective modular packagecover with first and second fastening sections located at opposing firstand second ends of the protective modular package cover and one or moresubassembly receiving sections disposed between the first and secondfastening sections is configured to fasten the protective modularpackage cover to a core. Referring now to FIG. 1, protective modularpackage cover 100, also referred to as a lid, a cover, or a clamp, inaccordance with certain embodiments is shown. There are two fasteningsections 110 shown, a first fastening section at a first end of theprotective modular package cover 100 and a second fastening section at asecond end of the protective modular package cover 100. Each fasteningsection 110 has a first foot surface 115 located on a bottom surface ofthe fastening section at an end of the protective modular package cover100 and is configured to make contact with a core layer; one or moretorque elements 120, shown here as four torque ribs, are disposed on thefoot surface 115 adjacent the outer edge of the respective end of theprotective modular package cover 100; and a mounting hole 125 thatextends through the fastening section from a top surface of thefastening section to the bottom surface of the fastening section, iscoupled to the torque element 120, and is configured to receive afastener, such as a bolt or screw 130 therein. Skirt 160 may be adecorative or cosmetic feature, or as illustrated in FIG. 2, may be usedto provide a better seal by buttressing the bond line between the crossmembers and encapsulated subassemblies. Optionally, the protectivemodular package cover 100 may have an orientation mark 135 as a feature.

Disposed between the first and second fastening sections are one or moresubassembly receiving sections 140 that are configured to receive one ormore subassemblies 180 that may be encapsulated therein. The one or moresubassemblies may be semiconductor packages or subassemblies, such as achip-and-wire package or an over-molded subassembly, including packagesor subassemblies suitable for radio frequency, microwave, optical, orother high power level applications. Each subassembly receiving sectionhas a cross member, such as lateral cross member 145 and transversecross member 150, formed along the underside of the protective modularpackage cover. As will be described in more detail, an adhesive layer170, such as epoxy polymer, is deposited on the cross member of eachsubassembly receiving section 140 to affix a subassembly 180 that willbe mounted in the subassembly receiving section.

In this particular embodiment, the subassembly receiving sections areillustrated as precision-locating pockets each having two lateral crossmembers 145 and a transverse cross member 150 formed along the undersideof the protective modular package cover 100. It is not necessary thatthe cross member of a subassembly receiving section comprise bothlateral and transverse cross members; this is illustrated by bolt downlid 1630 of FIG. 16, in which only lateral cross members are shown.Additionally, an internal support member 155 that separates therespective subassembly receiving sections 140 may be employed.

As will be shown in other drawings, the modular design of the protectivemodular package cover 100 allows for any number of subassemblies to bereceived and encapsulated in the subassembly receiving sections 140. Theone or more subassembly receiving sections 140 may be precision-locatingpockets suitable for receiving and encapsulating over-moldedsubassemblies, as illustrated in FIGS. 1-10 in which resin plasticover-molded packages are joined with the cover, which may be injectionmolded with a high performance engineering polymer, such as liquidcrystal polymer. Or, they may be air cavities formed by the joining of asidewall, such as a conductive leadframe injection molded liquid crystalpolymer material, to a conductive base material, as illustrated in FIGS.12, 14, and 16, suitable for receiving and encapsulating chip-and-wiresemiconductor packages. Either way, a way to secure the final assemblyto a core with a minimum of stress by the controlled application offorce to only the top surface of the semiconductor subassembly isprovided. While three subassembly receiving sections 140 are illustratedin FIG. 1, it is contemplated that any number may be employed asdetermined by the desired configuration of the assembly, including thenumber of assemblies desired, and that the dimensions and configurationsof each of the subassembly receiving sections are the same, allowing forscalability and reuse of pre-qualified functional blocks.

Referring now to FIG. 2, protective modular package cover 200illustrates that the bond lines provided by epoxy or other adhesivelayer 210 can be much more extensive, in effect maximizing the moisturepath length in the bond by maximizing the bond surface area between thecross members and the encapsulated subassemblies seated on the adhesivelayer 210. Also, it can be seen that the skirt elements 160 serve a moreimportant function than being merely decorative or cosmetic by servingas a structural element for establishment of the maximized adhesivelayer 210. Maximization of the adhesive layer serves to length the bondline and thus the path of moisture ingress. In this embodiment, theadhesive layer 210 is deposited on the cross members as well as alongand makes contact with an interior surface of the shirt elements 160,making the adhesive layer 210 contiguous the skirt elements as shown.

In FIG. 3, the cross-sectional view of protective modular package cover300 illustrates the enhanced epoxy or adhesive layer 210. It alsoillustrates other features of the protective modular package cover suchas a detailed view of torque element 120, mounting hole 125, fasteningelement 130, lateral cross members 145, internal support member 155, andfoot surface 115. In this particular embodiment, subassembly 180 isillustrated as an over-molded resin package subassembly.

Activation of one or more of the torque elements of the protectivemodular package cover transfers a downward clamping force that isgenerated at the first or second fastening elements to a top surface ofone or more subassemblies disposed in the one or more subassemblyreceiving sections. This transfer occurs via the one or more crossmembers of each of the one or more subassembly receiving sections. Moreparticularly, activation of the first or second torque elementstransfers the downward clamping force to a central portion of the top ofthe protective modular package cover and generates a distributeddownward clamping force that is distributed by the cross member of eachof the one or more subassembly receiving sections from the centralportion of the top of the protective modular package cover to the topsurface of the one or more subassemblies disposed in the one or moresubassembly receiving sections.

Referring now to protective modular package cover 400 of FIG. 4,insertion of and then activation of a fastener element 130, such as thebolt or screw, in its mounting hole 125 serves to activate the torquerib torque element 120 and result in generation of downward clampingforce. The rib adds resistance 410 to the screw torque and the footsurface 115 compresses downward 420. The downward clamping force istransferred 430 toward the center 450 of the lid to apply greaterpressure on top of the subassembly. This transferred downward clampingforce is distributed 440 each subassembly by the cross members, such aslateral and transverse cross members 145 and 150 of the one or moresubassembly receiving sections. In this manner, activation of a torqueelement of a fastening section transfers a downward clamping forcegenerated at a fastening element to a top surface of one or moresubassemblies disposed in the one or more subassembly receiving sectionsvia the cross member of each of the one or more subassembly receivingsections. Sufficient activation of the one or more torque elements 120of the fastening sections 110 operates to mount the protective modularpackage cover to the core, which may be a heat sink, a heat spreadingcore, a heat sinking core, or a base plate.

In accordance with embodiments described herein, a protective modularpackage assembly has one or more subassemblies, which may bechip-and-wire air-cavity semiconductor packages, chip-and-wiredielectric gel-filled cavities, or resin over-molded semiconductorsubassemblies as previously stated; a protective modular package coveras described above; and an adhesive layer for affixing the one or moresubassemblies to respective subassembly receiving sections of the one ormore subassembly receiving sections. The protective modular packagecover has first and second fastening sections located at opposing firstand second ends of the protective modular package cover with one or moretorque elements disposed on the first and second ends and is configuredto fasten the protective modular package cover to a core. The protectivemodular package cover further has one or more subassembly receivingsections disposed between the first and second fastening sections, witheach subassembly receiving section of the one or more subassemblyreceiving sections operable to receive a subassembly and having a crossmember formed along the underside of the protective modular packagecover.

Activation of the one or more torque elements of the fastening sectionsof the protective modular package cover transfers a downward clampingforce generated at the fastening elements to a top surface of one ormore subassemblies disposed in the one or more subassembly receivingsections via the cross member of each of the one or more subassemblyreceiving sections. Also, as previously described, activation of the oneor more torque elements transfers the downward clamping force to acentral portion of the top of the protective modular package cover andgenerates a distributed downward clamping force that is distributed bythe cross member of each of the one or more subassembly receivingsections from the central portion of the top of the protective modularpackage cover to the top surface of the one or more subassembliesdisposed in the one or more subassembly receiving sections. Sufficientactivation of the one or more torque elements mounts the protectivemodular package cover to a core.

FIGS. 5A-5F illustrate a plate set design in which a protective modularpackage assembly is shown. FIG. 5A illustrates an isometric view of topplate 510 and bottom plate 530 in closed position about protectivemodular package assembly 520. In FIG. 5B, the top and bottom plates 510,530 and assembly 520 are shown in an exploded view. The side view ofFIG. 5C illustrates plates 510, 530 in closed position. The top view oftop plate 510 in FIG. 5D further illustrates that top plate 510 holdsthe package protective cover 540. Adhesive pattern 525 is illustrateddeposited on the cross members of three subassembly receiving sections;again, as discussed previously, while three subassembly receivingsections are shown in this particular embodiment, it is contemplatedthat any number of subassembly receiving sections disposed between firstand second fastening sections may be used. In FIG. 5E, an isometric viewof top plate 510 again illustrates that top plate 510 holds protectivecover 540 as shown. FIG. 5F illustrates bottom plate 530, which holdsthe rest of the protective modular package assembly, including thesubassemblies 550 received by the subassembly receiving sections of thelid 540. The precise alignment of the subassemblies in the threesubassembly receiving section pockets can be seen. The positionalaccuracy afforded is advantageous, accommodating tight mechanicaltolerances.

As previously mentioned, the modular nature of the protective modularpackage assembly and the protective modular package cover thereofprovide for any number of subassemblies to be accommodated withoutrequiring a redesign of the lid and assembly. FIG. 6 illustrates anembodiment with one subassembly; FIG. 7 illustrates an embodiment withtwo subassemblies; and FIG. 8 illustrates an embodiment with threesubassemblies.

Referring now to FIGS. 6A-6G, in FIG. 6A an isometric view of theprotective modular package assembly with the top of cover 610 shown. InFIG. 6B, the central portion of the top of protective cover 610 isshown, as well as mounting hole 615 and orientation mark 630. FIG. 6Cillustrates a top view of the assembly in which a single subassembly 620is shown. FIG. 6D is a side view of the assembly. In FIG. 6E, the leads625 of the subassembly 620 are shown, as well as bolt/screw fastener635. FIG. 6F provides a side view of the assembly in which fastener 635and over-molded subassembly 620 are shown. In FIG. 6G, a bottom, x-rayview through subassemblies illustrates foot sections 640 with a total offour torque rib torque elements 645, transverse cross member 650,lateral cross members 655, subassembly 620 and fastener 635.

Referring now to FIGS. 7A-7F, a protective modular package assembly inwhich two subassemblies are encapsulated is shown. In FIG. 7A, anisometric view of the protective modular package assembly with the topof cover 710 shown. FIG. 7B illustrates a top view of the assembly inwhich two subassemblies 720 are shown. Due to all clamping force beingdistributed on the top surface of the lid 780, no pressure is applied ontop of the copper slug 770 of the subassemblies. FIG. 7C is a side viewof the assembly.

In FIG. 7D, the leads 725 of each of the two subassemblies 720 areshown, as well as bolt/screw fastener 735. FIG. 7E provides a side viewof the assembly in which fastener 735 and over-molded subassemblies 720are shown. In FIG. 7F, a bottom, x-ray view through subassembliesillustrates foot sections 740 with a total of four torque rib torqueelements 745, transverse cross members 750, lateral cross members 755,internal cross member 760, subassemblies 720, leads 725, and fastener735.

Referring now to FIGS. 8A-7G, a protective modular package assembly inwhich three subassemblies are encapsulated is shown. In FIG. 8A, anisometric view of the protective modular package assembly with the topof cover 810 shown. FIG. 8B illustrates a top view of the assembly inwhich three subassemblies 820 are shown. Due to all clamping force beingdistributed on the top surface of the lid 880, no pressure is applied ontop of the copper slug 870 of the subassemblies. FIG. 8C is a side viewof the assembly. The overall height of the assembly 880 may be maximizedto increase the thickness of the assembly to enhance the assemblystrength. In FIG. 8D, a view of the bottom of the lid cover illustratesprecision-locating pockets 815 configured to receive threesubassemblies, such as over-molded subassemblies.

In FIG. 8E, a isometric view of the modular package assembly shows leads825 and a central portion 810 of the lid, as well as bolt/screw fastener835. FIG. 8F provides a side view of the assembly in which fastener 835and over-molded subassemblies 820 are shown. In FIG. 8G, a bottom, x-rayview through subassemblies illustrates foot sections 840 with a total offour torque rib torque elements 845, transverse cross members 850,lateral cross members 855, internal cross member 860, subassemblies 820,leads 825, fastener 835, and optional orientation mark 830.

In FIG. 9, a top view 900 of a modular package assembly having threesubassemblies 920 with conductive leads 925 that electrically couple toconductor traces 930, such as on a printed circuit board, for example.Due to the modular nature of the lid and entire assembly, any number ofsemiconductor subassemblies 920 can be accommodated without a majorredesign of the package.

It is contemplated that a variety of types of subassemblies can beaccommodated, including a range of high power radio frequency (RF),microwave, and optical semiconductors. Thus, a package assembly of FIG.6 may have an average power of 50 W and a peak of 90 W, while theassembly of FIG. 7 houses two subassemblies and may have an averagepower of 95 W and peak power of 170 W and the assembly of FIG. 8, withthree subassemblies, may have an average power of 140 W and peak powerof 255 W. In FIG. 9, an RF amplifier having three independent stages ofpower gain is depicted schematically. It can be seen than an initialinput signal with a power level of 10 dBm is supplied by an externalcircuit supplied to the first subassembly, whereupon it is amplified by20 dB to a power level of 30 dBm. Subsequent amplification by the secondand third amplifier stages results in power gains of 10 dB and 7 dBrespectively, resulting in an average output power of 50 W (47 dBm) witha total amplification for the three stages being 37 dB.

FIGS. 10A and 10B illustrate 0 and 180 orientation views, respectively,of a representative RF straight lead subassembly. The modular designapproach is not sensitive to lead configuration and device rotation,being able to accommodate a wide variety of package types, including“straight lead,” “gull wing,” and “10 lead,” for example.

In addition to over-molded semiconductor subassemblies, shown in theabove figures, it is contemplated that chip-and-wire air-cavitysemiconductor subassemblies may be accommodated within one or moresubassembly receiving sections as well.

FIG. 11 shows a prior art completed assembly of a dedicated,non-modular, non-customizable leaded assembly 1100, in which one or moresemiconductor devices are encapsulated by way of an air-cavity. Theconstituent parts of non-isolated ceramic package assembly 1100 includenon-isolated metal flange or base 1110, a ringframe/sidewall 1120 withleads 1125, a ceramic lid 1130, and an air cavity 1140 formed by thejoining of sidewall 1120 to conductive base 1110 as shown. This designis not modular and cannot be easily changed to accommodate differentsubassemblies and overall package configurations once set. Oncedesigned, it is fixed. The flange base material can be expected to bequite expensive due to its complex shape.

FIGS. 12A and 12B, in contrast to FIG. 11, illustrate a modular packageassembly 1200 in which one or more semiconductor devices areencapsulated by way of an air-cavity, in accordance with variousembodiments described herein. In FIG. 12A, a top view of the completeassembly 1200 is comprised of a non-isolated flange/base 1210 to which aringframe/sidewall 1220 is joined to form an air cavity subassembly1240, a subassembly receiving section configured to receive thesubassembly, and serving as a cover, yielding a non-isolated packagesubassembly.

The leaded sidewall may consist of a conductive leadframe that isinjection molded with a high performance engineering polymer, such asliquid crystal polymer (LCP) material, providing mechanical support andelectrical isolation for individual leads. The sidewall 1120accommodates multiple leads and electrically isolates leads from baselayer 1210. When the sidewall is joined to the base 1210, it serves asan additional layer of protection to the encapsulated semiconductorsubassembly therein, by forming an air-cavity in which additionalcomponents, such as wirebonds, can be used for added functionality ofthe final device. The air cavity formed by sidewall 1220 and base 1210can accommodate any subassembly package desired.

The bolt-down lid 1230 is an exemplary protective modular package coveras described above and facilitates bolt down of the package assembly toa core from the top. This particular assembly encapsulates twosubassemblies as illustrated by leads 1225. The cover 1230 seals the aircavity and provides a way to secure the final assembly to a core, suchas a heat spreading core, with a minimum of stress to the semiconductormaterials, as previously described. This is accomplished by applyingpressure to only the top surface of the sidewall layer. A bottom view ofassembly 1200 is shown in FIG. 12B.

It can thus be seen that the air cavity formed by a sidewall element ofa subassembly joined to a base element of the subassembly is sealed byreceipt of the subassembly by a subassembly receiving section of the oneor more subassembly receiving sections and securing the protectivemodular package cover to a modular package assembly comprising thesubassembly. The sidewall element can be a leaded sidewall, such as aconductive leadframe injection molded with a high performanceengineering polymer, such as liquid crystal polymer material.

FIG. 13 shows a prior art completed assembly of a dedicated,non-modular, non-customizable leaded assembly 1300 in which onechip-and-wire subassembly is encapsulated. Its constituent parts areshown as a non-isolated flange or base 1310, a ringframe/sidewall 1320,a ceramic lid 1330, and an air cavity 1340 formed by the joining ofsidewall 1320 to conductive base 1310 as shown. This design is notmodular and cannot be easily changed to accommodate differentsubassemblies and overall package configurations once set.

FIG. 14, in contrast to FIG. 13, illustrates a modular package assembly1400 in which one chip-and-wire semiconductor subassembly isencapsulated, in accordance with various embodiments described herein.In FIG. 14, a top view of the complete assembly 1400 is comprised of anon-isolated flange/base 1210 to which a ringframe/sidewall 1420 isjoined to form air cavity subassembly 1440, a subassembly receivingsection configured to receive the subassemblies, yielding a non-isolatedpackage assembly. The bolt-down lid 1430 is an exemplary protectivemodular package cover as described above.

Referring now to FIG. 15, a prior art assembly of a dedicated,non-modular, non-customizable leaded assembly 1500 is shown. Itsconstituent parts are shown as a non-isolated flange or base 1510, aringframe/sidewall 1520, a ceramic lid 1530, and an air cavity 1540formed by the joining of sidewall 1520 to conductive base 1510 as shown.This design is not modular and cannot be easily changed to accommodatedifferent subassemblies and overall package configurations once set.

In contrast, FIG. 16 illustrates a modular package assembly 1600, inaccordance with various embodiments described herein. It is important tonote, in contrast to FIG. 15, that no flange is needed, as the bottom ofthe subassembly provides the needed electrical contact. Also, nosidewall is needed to form an air cavity, as the lid has been designedto provide this feature. The lid may be formed of high performanceengineering polymer, such as a liquid crystal polymer (LCP) material,which is adhesively joined directly to the base element, with no needfor an interposing sidewall as the sidewall function is provided by thebase element. Assembly 1600, then, is comprised of an isolated leadframe/base subassembly 1620, and a bolt-down lid 1630. The air cavity1640 is formed on the underside of bolt-down lid 1630. A round,insulated base structure accommodates many leads inside the air cavityto a round piece of ceramic. In this embodiment, a torque element islocated on the foot section at each end of the package assembly.

It can be seen from the above description and also with reference toFIGS. 17 and 18, that the modular package assembly described hereinaccommodates embodiments with both an isolated flange/base and anon-isolated flange/base, as in FIG. 17, and that sidewalls withcustomizable leadframes are interchangeable so as to accommodatedifferent subassembly configurations, as in FIG. 18.

In contrast to the highly shaped, expensive base material shown in FIGS.11 and 13, the formed air cavity of FIGS. 12 and 14 provides a simple,relatively inexpensive structure that can accommodate any subassemblypackage desired. By elimination of the metal flange structure of theprior art, the base can accommodate both isolated and non-isolatedinfrastructures. The lid cover and sidewalls can be easily interchangedto accommodate many different subassembly package outlines. And, asnoted with regard to FIG. 16, in contrast to FIG. 15, no flange isneeded.

As used herein in FIGS. 12 and 14, the term base can be isolated ornon-isolated and encompasses a variety of terms, including but notlimited to, flange, thermal base, thermal plane, High TemperatureCo-fired Ceramic (HTCC), Low Temperature Co-fired Ceramic (LTCC), metalor metallic flange, and ceramic flange, and may or may not beelectrically insulating, and with or without thermally enhanced layers.The base of a subassembly may be one or more metal layers.

In accordance with various embodiments, a method of manufacturing aprotective modular package cover in accordance with a modular design isprovided. The protective modular package cover has one or moresubassembly receiving sections configured to receive a subassembly ofone or more subassemblies and have a cross member formed along theunderside of the protective modular package cover. An adhesive layer isselectively applied to the cross member of each subassembly receivingsection of the one or more subassembly receiving sections that willreceive a subassembly of the one or more subassemblies to form anadhesive layer of the protective modular package cover. The one or moresubassemblies in the one or more subassembly receiving sections of theprotective modular package cover are seated on the selectively appliedadhesive layer to encapsulate them within the protective modular packagecover to generate a protected package assembly. Controlled applicationof a distributed downward clamping force applied to the top surfaces ofthe one or more subassemblies received by the protective modular packagecover is useful for mounting the protected package assembly to a corethrough activation of one or more fastener elements and the crossmembers of the subassembly receiving sections. The protected packageassembly can be isothermally sealed to create a high reliability jointbetween the protective modular package cover and the one or moresubassemblies encapsulated in the protected package assembly. Theisothermal sealing process controls the formation of high reliabilityjoints between layers of the assembly.

Referring now to FIG. 19, a method of manufacturing a protected packageassembly in accordance with various embodiments is shown in flow 1900.At Block 1910, a protective modular package cover in accordance with amodular design is provided. The protective modular package cover havingone or more subassembly receiving sections configured to receive asubassembly of one or more subassemblies and have a cross member formedalong the underside of the protective modular package cover. Next, atBlock 1920, an adhesive is selectively applied to the cross member ofeach subassembly receiving section of the one or more subassemblyreceiving sections that will receive a subassembly of the one or moresubassemblies to form an adhesive layer of the protective modularpackage cover. At Block 1930, the one or more subassemblies areencapsulated in the one or more subassembly receiving sections of theprotective modular package cover on the selectively applied adhesivelayer to generate a protected package assembly.

Controlled application of a distributed downward clamping force appliedto the top surfaces of the one or more subassemblies received by theprotective modular package cover is useful for mounting the protectedpackage assembly to a core through activation of one or more fastenerelements and the cross members of the subassembly receiving sections atBlock 1940. As previously described, a downward clamping force appliedat one or more fastener elements of the protective modular package coveris transferred by one or more torque elements of the one or morefastener elements to a central top portion of the protective modularpackage cover and distributed as the distributed downward clamping forceto the top surfaces of the one or more subassemblies by the cross memberof each subassembly receiving section of the one or more subassemblyreceiving sections. This may further comprise engaging one or morefastener elements at one or more mounting holes of the one or morefastening elements of the protective modular package cover to generatethe downward clamping force useful for mounting the protected packageassembly to the core, wherein engaging the one or more fastener elementsactivates one or more torque elements at the one or more mounting holesof the protective modular package cover that transfer the downwardclamping force to a central portion of the top of the modular packageprotected cover where it is distributed as a distributed downwardclamping force by the cross member of each subassembly receiving sectionof the one or more subassembly receiving sections that will receive asubassembly of the one or more subassemblies.

The protected package assembly is isothermally sealed at Block 1950 tocreate a high reliability joint between the protective modular packagecover and the one or more subassemblies encapsulated in the protectedpackage assembly.

The method of FIG. 19 may further include providing the one or moresubassemblies to be received by the one or more subassembly receivingsections, wherein each subassembly of the one or more subassemblies isformed by joining a sidewall element of the subassembly to a baseelement of the subassembly to create an air cavity; and sealing the aircavity of each of subassembly by receiving the one or more subassembliesby the one or more subassembly receiving elements and securing theprotective modular package cover to the core. As has been discussed, thesidewall element may be a conductive leadframe injection molded with ahigh performance engineering polymer, such as a liquid crystal polymermaterial.

A user/designer may make use of software modeling tools, including two-and three-dimensional CAD tools like Autodesk, to design through userinput design data provided to such software tools modular packageassemblies of different configurations and dimensions.

With regard to the modular design referred to at Block 1910 of FIG. 19,flow 2000 of FIG. 20 discusses this design. At Block 2010, a packageoutline of a modular package assembly is determined by receiving packageoutline user input design data at a design tool. The seating plane andoverall package length (L) characteristics of the modular packageassembly is determined at Block 2020 by receiving seating plane andpackage length design data at a design tool, and the minimum packageheight (H) of the modular package assembly is calculated from theoverall package length of the modular package assembly contained in thereceived seating plane and package length user input design data, atBlock 2030. A guideline for this calculation can be H≧0.2 L, forexample. This equation can be modified according to the finalformulation of molded materials and epoxy adhesives, if desired.

At Block 2040, dimensions and configurations of one or moresubassemblies of the modular package assembly are design usingsubassembly user input design data provided to the design tool. Aspreviously shown, each subassembly of the one or more subassembliescomprises a base element, a sidewall element coupled to the baseelement, and a semiconductor device disposed within and coupled to thesidewall element and the base element.

Designing the one or more subassemblies may include designing the baseelement of the one or more subassemblies having an electricalconductivity characteristic and a thermal conductivity characteristic;determining the dimensions of the base element taking into account theelectrical conductivity characteristic and the thermal conductivitycharacteristic of the designed base element; and designing the sidewallelement that is coupled to the base element taking into account theelectrical conductivity characteristic of the base element, the sidewallelement comprising a leadframe element that is electrically coupled tothe semiconductor device.

The base, which may be a thermal base, a flange, thermal plane, HTCC, orLTCC, for example, is designed at Block 2040 to support thesemiconductor subassemblies to be encapsulated in the assembly. The baseis configured to support one or more subassemblies received by one ormore subassembly receiving sections of a subassembly support element ofa mechanical layer of the plurality of mechanical layers of theprotective modular package cover.

The electrical conductivity characteristic of the base element is eithernon-isolated or isolated, as indicated in FIG. 17. The thermalconductivity characteristic may be a thermal conductivity rating of thebase element. The base layer may be one or more layers. The dimensionsof the base element comprise the width, length and thickness of the baseelement, which may be determined by a thermal simulation analysisperformed on the base element that takes into account the electricalconductivity characteristic and the thermal conductivity characteristicof the designed base element.

If needed, at Block 2040 one or more injection molded sidewalls for theone or more subassembly receiving sections of the subassembly supportelement of the protective modular package cover are designed, the one ormore injection molded sidewalls configured to receive one or moresubassemblies. As previously discussed in connection with FIG. 16, forexample, a sidewall is not required to form an air cavity for cavitationof a chip-and-wire subassembly, as the base performs this function. Aspreviously indicated, the sidewall element may be an injection moldedsidewall. Moreover, the sidewall element may be a ringframe layer of theone or more subassemblies as shown in several of the drawings.

At Block 2050, the dimensions and configuration of a plurality ofmechanical layers of the protective modular package cover given thedefined package outline, the seating plane, overall package length, theminimum package height of the modular package assembly, and the designedsubassemblies are defined. This may comprise partitioning the desiredassembly into three volumes corresponding to the mechanical layers,which may include a fastening element, a subassembly support elementhaving one or more subassembly receiving sections of definedconfiguration and dimension with each subassembly receiving sectionhaving a cross member, and an electrical connections element of theprotective modular package cover. The fastening element includes the lidwith fastening or bolting features in place of a flange and include thecover (lid). The subassembly support element provides semiconductordevice support and may be an air cavity configured to encapsulate achip-and-wire assembly, in the case of an air cavity subassemblyreceiving section, or a precision-locating pocket that encapsulated anover-molded subassembly. The electrical connections element consists ofwirebond regions or openings through which leads may pass. In the caseof a sidewall formed, for example, the electrical connections may beinjection molded into an insulating polymer sidewall with layerthickness of approximately 0.3 H.

At Block 2060, an adhesive deposition strategy to join together theplurality of mechanical layers of the protective modular package coveris designed. The adhesive deposition strategy is chosen to permanentlyjoin together the various mechanical layers of the assembly along bondlines. The bond line features are accordingly incorporated into the molddesign. The bond lines may be adjusted as needed to maximize moisturepath length and to maximize surface area at the joints between themechanical layers.

At Block 2070, the protective modular package cover is designed inaccordance with the dimensions and configuration of the plurality ofmechanical layers as set forth above.

At Block 2080, the configuration and dimensions of the modular packageassembly and the adhesive deposition strategy are incorporated into amanufacturing assembly process configured to manufacture the modularpackage assembly. This may include incorporating the joining steps,including bonding, into an manufacturing assembly line to prepare formanufacturing fixture design changes or for the design of new fixturesif needed to accommodate joining together the mechanical layers of thedesired assembly.

Once the modular portions of a modular package assembly have beendesigned, as shown in FIG. 20, a user may again make use of softwaremodeling tools, including two- and three-dimensional CAD tools likeAutodesk, can design through user input design data provided to suchsoftware tools modular package assemblies of different configurationsand dimensions, all making use of previously designed modules, such asthe fastening sections and the subassembly receiving sections of theassembly.

Referring now to flow 2100 of FIG. 21, user input design data thatdefines the configuration and dimensions of a modular package assemblyhaving fastening sections of predetermined dimension and configuration,one or more subassembly receiving sections each suitable for receiving asubassembly of predetermined dimension and configuration with eachsubassembly receiving section having at least one cross member, and oneor more subassemblies of predetermined dimension and configuration isreceived at a design tool at Block 2110.

The configuration of the modular package assembly includes a protectivemodular package cover of user defined dimension and configuration,reflected in the user input design data provided to the design tool. Theprotective modular package cover has first and second fastening sectionsof predetermined dimension and configuration, one or more subassemblyreceiving sections of predetermined dimension and configuration disposedbetween said first and second fastening sections with each subassemblyreceiving section of the one or more subassembly receiving sectionshaving a cross member of predetermined dimension and configurationformed along the underside of the protective modular package cover andconfigured to receive a subassembly, and one or more subassemblies ofpredetermined dimension and configuration to be received by the one ormore subassembly receiving sections. The configuration and dimensions ofthe modular package assembly are determined by the user defineddimensions of the protective modular package cover, the predetermineddimension and configuration of the one or more subassembly receivingsections, and the predetermined dimension and configuration of the oneor more subassemblies. The predetermined dimension and configuration ofthe one or more subassembly receiving sections accommodate thepredetermined dimension and configuration of the one or moresubassemblies.

At Block 2120, an adhesive deposition strategy for deposition of anadhesive layer to the cross members of the one or more subassemblyreceiving sections sufficient to affix the top side of the one or moresubassemblies to the cross member on the underside of a correspondingsubassembly receiving section of the one or more subassembly receivingsections is determined. The adhesive deposition strategy is a strategyfor deposition of an epoxy polymer layer to the cross members of the oneor more subassembly receiving sections. At Block 2130, the configurationand dimensions of the modular package assembly and the adhesivedeposition strategy are incorporated into a manufacturing assemblyprocess configured to manufacture the modular package assembly.

Referring to FIG. 22, flow 2200 recites a method for design andmanufacture of a desired modular assembly. As below, at Block 2210,input design data to an input interface of a design tool defines theconfiguration and dimensions of a modular package assembly. User inputdesign data that defines the configuration and dimensions of a modularpackage assembly having fastening sections of predetermined dimensionand configuration, one or more subassembly receiving sections eachsuitable for receiving a subassembly of predetermined dimension andconfiguration with each subassembly receiving section having at leastone cross member, and one or more subassemblies of predetermineddimension and configuration is received. The predetermined dimension andconfiguration of the one or more subassembly receiving sectionsaccommodate the predetermined dimension and configuration of the one ormore subassemblies. At Block 2220, an adhesive deposition strategy fordeposition of an adhesive layer to the cross members of the one or moresubassembly receiving sections sufficient to affix the top side of theone or more subassemblies to the cross member on the underside of acorresponding subassembly receiving section of the one or moresubassembly receiving sections is determined. At Block 2230, theconfiguration and dimensions of the modular package assembly and theadhesive deposition strategy are incorporated into a manufacturingassembly process configured to manufacture the modular package assembly.Next, at Block 2240, the adhesive layer is selectively applied to thecross members of the one or more subassembly receiving sections inaccordance with the adhesive deposition strategy.

At Block 2250, the one or more subassemblies are encapsulated in the oneor more subassembly receiving sections of the protective modular packagecover on the selectively applied adhesive layer to generate a protectedpackage assembly. At Block 2260, controlled application of a distributeddownward clamping force applied to the top surfaces of the one or moresubassemblies received by the protective modular package cover anduseful for mounting the protected package assembly to a core throughactivation of one or more fastener elements and the cross members of thesubassembly receiving sections occurs.

Modification of a given design can occur after the modules of anassembly have been specified and this flexibility is one of theadvantages to the approach. This is reflected in FIGS. 23 and 24.

Referring now to flow 2300 of FIG. 23, at Block 2310 user input designdata is received at the design tool that defines the configuration anddimensions of a modular package assembly having fastening sections ofpredetermined dimension and configuration, one or more subassemblyreceiving sections each suitable for receiving a subassembly ofpredetermined dimension and configuration with each subassemblyreceiving section having at least one cross member, and one or moresubassemblies of predetermined dimension and configuration. Thepredetermined dimension and configuration of the one or more subassemblyreceiving sections accommodate the predetermined dimension andconfiguration of the one or more subassemblies. At Block 2320, anadhesive deposition strategy for deposition of an adhesive layer to thecross members of the one or more subassembly receiving sectionssufficient to affix the top side of the one or more subassemblies to thecross member on the underside of a corresponding subassembly receivingsection of the one or more subassembly receiving sections is determined.At Block 2330, the configuration and dimensions of the modular packageassembly and the adhesive deposition strategy into a manufacturingassembly process configured to manufacture the modular package assemblyare incorporated. At Block 2340, design input data of a modified modularpackage assembly is received. The configuration and dimensions of themodified modular package assembly are different from the configurationand dimensions of the modular package assembly but the predetermineddimensions of first and second fastening sections and of one or moresubassembly receiving sections of the modified modular package assemblyremain unchanged from the modular package assembly. At Block 2350, amodified adhesive deposition strategy for deposition of a modifiedadhesive layer to the cross members of the one or more subassemblyreceiving sections sufficient to affix the top side of the one or moresubassemblies to the cross member on the underside of a correspondingsubassembly receiving section of the one or more subassembly receivingsections for the modified modular package assembly is determined. Theconfiguration and dimensions of the modified modular package assemblyand the modified adhesive deposition strategy are incorporated into amodified manufacturing assembly process configured to manufacture themodified modular package assembly at Block 2360.

Flow 2400 of FIG. 24 provides for the modified design of the modularassembly and subsequent manufacturing thereof. At Block 2410, user inputdesign data is received at the user interface of a design tool thatdefines the configuration and dimensions of a modular package assemblyhaving fastening sections of predetermined dimension and configuration,one or more subassembly receiving sections each suitable for receiving asubassembly of predetermined dimension and configuration with eachsubassembly receiving section having at least one cross member, and oneor more subassemblies of predetermined dimension and configuration. Thepredetermined dimension and configuration of the one or more subassemblyreceiving sections accommodate the predetermined dimension andconfiguration of the one or more subassemblies. At Block 2420, anadhesive deposition strategy for deposition of an adhesive layer to thecross members of the one or more subassembly receiving sectionssufficient to affix the top side of the one or more subassemblies to thecross member on the underside of a corresponding subassembly receivingsection of the one or more subassembly receiving sections is determined.At Block 2430, the configuration and dimensions of the modular packageassembly and the adhesive deposition strategy are incorporated into amanufacturing assembly process configured to manufacture the modularpackage assembly. At Block 2440, user input design data of a modifiedmodular package assembly is received at the user interface of a designtool. The configuration and dimensions of the modified modular packageassembly are different from the configuration and dimensions of themodular package assembly but the predetermined dimensions of first andsecond fastening sections and of one or more subassembly receivingsections of the modified modular package assembly remain unchanged fromthe modular package assembly. At Block 2450, a modified adhesivedeposition strategy for deposition of a modified adhesive layer to thecross members of the one or more subassembly receiving sectionssufficient to affix the top side of the one or more subassemblies to thecross member on the underside of a corresponding subassembly receivingsection of the one or more subassembly receiving sections for themodified modular package assembly is determined. The configuration anddimensions of the modified modular package assembly and the modifiedadhesive deposition strategy is incorporated into a modifiedmanufacturing assembly process configured to manufacture the modifiedmodular package assembly at Block 2460. An adhesive layer is selectivelyapplied to the cross members of the one or more subassembly receivingsections in accordance with the modified adhesive deposition strategy atBlock 2470. At Block 2480, one or more subassemblies are encapsulated inthe one or more subassembly receiving sections of the protective modularpackage cover on the selectively applied adhesive layer to generate aprotected package assembly. Finally, at Block 2490, controlledapplication of a distributed downward clamping force is applied to thetop surfaces of the one or more subassemblies received by the protectivemodular package cover and useful for mounting the protected packageassembly to a core through activation of one or more fastener elementsand the cross members of the subassembly receiving sections.

The processes and methodologies previously described can be carried outon a programmed general purpose computer system, such as the exemplarycomputer system 2500 depicted in FIG. 25. Examples of such a programmedgeneral purpose computer system may be a software modeling tool,including two- and three-dimensional CAD tools like Autodesk, which candesign through user input design data provided to an interface of thetool. Computer System 2500 has a central processor unit (CPU) 2510 withan associated bus 2515 used to connect the CPU 2510 to Random AccessMemory (RAM) 2520 and/or Non-Volatile Memory (NVM) 2530 in a knownmanner. An output mechanism at 2540 may be provided in order to displayand/or print output for the computer user. Similarly, input devices suchas keyboard and mouse 2550 may be provided for the input of informationby the computer user. Computer 2500 may also have disc storage 2560 forstoring large amounts of information including, but not limited to,program files and data files. Computer system 2500 may also be coupledto a local area network (LAN) and/or wide area network (WAN) and/or theInternet using a network connection 2570 such as an Ethernet adaptercoupling computer system 2500, possibly through a fire wall. The exactarrangement of the components of FIG. 25 will depend upon the functioncarried out in the particular components shown. Additionally, thenetwork connection 2570 and network interface may depend upon whetherthe associated components are situated locally or remotely, with datapassing to and from the processor system 2500 via line 2580.

Software and/or firmware embodiments may be implemented using aprogrammed processor executing programming instructions that in certaininstances are broadly described above in flow chart form that can bestored on any suitable electronic or computer readable storage medium,such as, for instance, disc storage, Read Only Memory (ROM) devices,Random Access Memory (RAM) devices, network memory devices, opticalstorage elements, magnetic storage elements, magneto-optical storageelements, flash memory, core memory and/or the equivalent volatile andnon-volatile storage technologies, and/or can be transmitted over anysuitable electronic communication medium. However, those skilled in theart will appreciate, upon consideration of the present teaching, thatthe processes described above can be implemented in any number ofvariations and in many suitable programming languages without departingfrom embodiments described herein. For example, the order of certainoperations carried out can often be varied, additional operations can beadded or operations can be deleted without departing from certainembodiments disclosed herein. Error trapping can be added and/orenhanced and variations can be made in user interface and informationpresentation without departing from certain embodiments describedherein. Such variations are contemplated and considered equivalent.

The representative embodiments, which have been described in detailherein, have been presented by way of example and not by way oflimitation. It will be understood by those skilled in the art thatvarious changes may be made in the form and details of the describedembodiments resulting in equivalent embodiments that remain within thescope of the appended claims.

1. A protective modular package assembly, comprising: one or moresubassemblies, wherein each subassembly of the one or more subassembliescomprises a base element, a sidewall element coupled to the baseelement, and a semiconductor device disposed within and coupled to thesidewall element and the base element; a protective modular packagecover, comprising: first and second fastening sections located atopposing first and second ends of the protective modular package cover,having one or more torque elements disposed on one or more of the firstand second ends, and configured to fasten the protective modular packagecover to a core; and one or more subassembly receiving sections disposedbetween the first and second fastening sections and each subassemblyreceiving section of the one or more subassembly receiving sectionsoperable to receive a subassembly of the one or more subassemblies,wherein each subassembly receiving section of the one or moresubassembly receiving sections comprises a cross member formed along theunderside of the protective modular package cover; and an adhesive layerconfigured to affix the one or more subassemblies to respectivesubassembly receiving sections of the one or more subassembly receivingsections; wherein the one or more torque elements of the first andsecond fastening sections are configured to transfer a downward clampingforce generated at the first or second fastening elements to a topsurface of one or more subassemblies disposed in the one or moresubassembly receiving sections via the cross member of each of the oneor more subassembly receiving sections.
 2. The assembly of claim 1,wherein activation of the one or more torque elements transfers thedownward clamping force to a central portion of the top of theprotective modular package cover and generates a distributed downwardclamping force that is distributed by the cross member of each of theone or more subassembly receiving sections from the central portion ofthe top of the protective modular package cover to the top surface ofthe one or more subassemblies disposed in the one or more subassemblyreceiving sections.
 3. The assembly of claim 1, wherein sufficientactivation of the one or more torque elements mounts the protectivemodular package cover to the heat sink.
 4. The assembly of claim 1,wherein the distributed downward clamping force is generated byactivation of the one or more torque elements by insertion of a fastenerin a mounting hole of the first or second fastening sections andengagement of the one or more torque elements by the fastener.
 5. Theassembly of claim 1, wherein the cross member of each subassemblyreceiving section further comprises a lateral cross member and atransverse cross member formed along the underside of the protectivemodular package cover;
 6. The assembly of claim 1, wherein the crossmember comprises a lateral cross member.
 7. The assembly of claim 6,wherein the lateral cross member is formed by two or more lateral crossmembers.
 8. The assembly of claim 1, wherein two or more subassemblyreceiving sections of the protective modular package cover are separatedby one or more internal support members.
 9. The assembly of claim 1,wherein the one or more subassembly receiving sections are formed withinan underside of the protective modular package cover.
 10. The assemblyof claim 1, wherein each subassembly receiving sections of theprotective modular package cover is separated by first and second skirtelements formed along first and second sides of the protective modularpackage cover.
 11. The assembly of claim 10, wherein the adhesive layeris formed contiguous the first and second skirt elements.
 12. Theassembly of claim 1, wherein the first fastening section comprises: afirst foot located on a bottom surface of the first fastening section atthe first end of the protective modular package cover and configured tomake contact with the heat sink; a first torque element disposed on thefirst foot adjacent the outer edge of the first end of the protectivemodular package cover; and a first mounting hole that extends throughthe first fastening section from a top surface of the first fasteningsection to the bottom surface of the first fastening section, is coupledto the first torque element, and is configured to receive a firstfastener therein; and the second fastening section comprises: a secondfoot located on a bottom surface of the second fastening section at thesecond end of the protective modular package cover and configured tomake contact with the heat sink; a second torque element disposed on thesecond foot adjacent the outer edge of the second end of the protectivemodular package cover; and a second mounting hole that extends throughthe second fastening section from a top surface of the second fasteningsection to the bottom surface of the second fastening section, iscoupled to the second torque element, and is configured to receive asecond fastener therein.
 13. The assembly of claim 12, wherein the firstand second torque elements comprise first and second torque ribs. 14.The assembly of claim 12, wherein the first torque element furthercomprises first and second torque ribs and the second torque elementfurther comprises third and fourth torque ribs.
 15. The assembly ofclaim 10, wherein the first and second fasteners are screws or mountingbolts.
 16. The assembly of claim 1, wherein the base element of the oneor more subassemblies has an electrical conductivity characteristic anda thermal conductivity characteristic.
 17. The assembly of claim 16,wherein the electrical conductivity characteristic of the base elementis either non-isolated or isolated.
 18. The assembly of claim 16,wherein the thermal conductivity characteristic is a thermalconductivity rating of the base element.
 19. The assembly of claim 16,wherein the base element has multiple base layers.
 20. The assembly ofclaim 1, wherein the sidewall element is an injection molded sidewall.21. The assembly of claim 1, wherein the sidewall element is a ringframelayer of the one or more subassemblies.
 22. The assembly of claim 1,wherein the sidewall element joined to the base element of a subassemblyto the one or more subassemblies creates an air cavity that is sealed byreceipt of the subassembly by a subassembly receiving section of theprotective modular package cover and securing the protective modularpackage cover to the modular package assembly.
 23. The assembly of claim22, wherein the sidewall element is a leaded sidewall.
 24. The assemblyof claim 23, wherein the leaded sidewall comprises a conductiveleadframe injection molded with a liquid crystal polymer material. 25.The assembly of claim 1, wherein a subassembly of the one or moresubassemblies is an overmolded subassembly.
 26. The assembly of claim 1,wherein the one or more subassembly receiving sections comprise one ormore precision locating pockets of the protective modular package coverconfigured to receive one or more overmolded subassemblies.
 27. Theassembly of claim 1, wherein the core is a heat sink, heat sinking core,heat spreading core, a thermal base, or base plate.